Question

我有一个存储过程，我有一个临时表，我需要更新“day_name”列的值。循环throug临时表并更新值

这是数据的示例（有多个学生姓名）：

student        StudentID    courseID    course_name           period    day_name
Bray, Clifford  14088      10064    Physical Education 9GYM     1         A
Bray, Clifford  14088      10064    Physical Education 9GYM     1         B
Bray, Clifford  14088      10064    Physical Education 9GYM     1         C
Bray, Clifford  14088      10064    Physical Education 9GYM     1         D
Bray, Clifford  14088      10064    Physical Education 9GYM     2         A
Bray, Clifford  14088      10064    Physical Education 9GYM     2         B
Bray, Clifford  14088      10064    Physical Education 9GYM     2         C
Bray, Clifford  14088      10064    Physical Education 9GYM     2         D
Bray, Clifford  14088      10065    Physical Education 11GYM    3         B
Bray, Clifford  14088      10065    Physical Education 11GYM    3         D
Bray, Clifford  14088      10065    Physical Education 11GYM    5         A
Bray, Clifford  14088      10065    Physical Education 11GYM    5         C
Bray, Clifford  14088      10065    Physical Education 11GYM    6         A
Bray, Clifford  14088      10065    Physical Education 11GYM    6         B
Bray, Clifford  14088      10065    Physical Education 11GYM    6         C
Bray, Clifford  14088      10065    Physical Education 11GYM    6         D
Bray, Clifford  14088      10059    Health 9P373                7         A
Bray, Clifford  14088      10059    Health 9P373                7         B
Bray, Clifford  14088      10059    Health 9P373                7         C

我希望数据是这样的：

student        studentID    courseID    course_name         period  day_name
Bray, Clifford  14088      10064    Physical Education 9GYM     1    ABCD
Bray, Clifford  14088      10064    Physical Education 9GYM     2    ABCD
Bray, Clifford  14088      10065    Physical Education 11GYM    3    BD
Bray, Clifford  14088      10065    Physical Education 11GYM    5    AC
Bray, Clifford  14088      10065    Physical Education 11GYM    6    ABCD
Bray, Clifford  14088      10059    Health 9P373                7    ABC

非常感谢提前:) 请帮忙......

Answer 1

鉴于您拥有有限的日期名称列表，最简单的方法可能是明确的聚合：

select student, StudentID, courseID, course_name, period,
       (max(case when day_name = 'A' then day_name else '' end) +
        max(case when day_name = 'B' then day_name else '' end) +
        max(case when day_name = 'C' then day_name else '' end) +
        max(case when day_name = 'D' then day_name else '' end)
       ) as days        
from table t
group by student, StudentID, courseID, course_name, period;

如果您希望表格看起来像这样，我建议您创建一个新表格。修改原始版本并不合理 - 您必须删除行以及修改或插入值。

Answer 2

以此为输入：

DECLARE @STUDENTS TABLE (STUDENT VARCHAR(20), STUDENTID INT, COURSEID INT, COURSE_NAME VARCHAR(MAX), PERIOD INT, DAY_NAME CHAR(1))

INSERT @STUDENTS VALUES

('Bray, Clifford', 14088, 10064, 'Physical Education 9GYM', 1, 'A'),
('Bray, Clifford', 14088, 10064, 'Physical Education 9GYM', 1, 'B'),
('Bray, Clifford', 14088, 10064, 'Physical Education 9GYM', 1, 'C'),
('Bray, Clifford', 14088, 10064, 'Physical Education 9GYM', 1, 'D'),
('Bray, Clifford', 14088, 10064, 'Physical Education 9GYM', 2, 'A'),
('Bray, Clifford', 14088, 10064, 'Physical Education 9GYM', 2, 'B'),
('Bray, Clifford', 14088, 10064, 'Physical Education 9GYM', 2, 'C'),
('Bray, Clifford', 14088, 10064, 'Physical Education 9GYM', 2, 'D'),
('Bray, Clifford', 14088, 10065, 'Physical Education 11GYM', 3, 'B'),
('Bray, Clifford', 14088, 10065, 'Physical Education 11GYM', 3, 'D'),
('Bray, Clifford', 14088, 10065, 'Physical Education 11GYM', 5, 'A'),
('Bray, Clifford', 14088, 10065, 'Physical Education 11GYM', 5, 'C')

此查询：

SELECT STUDENT, STUDENTID, COURSEID, COURSE_NAME, PERIOD,
      (SELECT DISTINCT '' + DAY_NAME
       FROM @STUDENTS          
       WHERE S.STUDENTID = STUDENTID AND S.COURSEID = COURSEID AND S.PERIOD = PERIOD
       FOR XML PATH ('')) AS DAYS
FROM @STUDENTS AS S
GROUP BY STUDENT, STUDENTID, COURSEID, COURSE_NAME, PERIOD

产生以下输出：

    STUDENT        STUDENTID    COURSEID COURSE_NAME                PERIOD  DAYS
   ------------------------------------------------------------------------------
    Bray, Clifford 14088        10064    Physical Education 9GYM    1       ABCD
    Bray, Clifford 14088        10064    Physical Education 9GYM    2       ABCD
    Bray, Clifford 14088        10065    Physical Education 11GYM   3       BD
    Bray, Clifford 14088        10065    Physical Education 11GYM   5       AC

更新具有多行的字段值

2 个答案: